for people interested in a cheat mode, many manufacturers will also mold a chart of allowable box fill with #14, #12, and #10 conductors inside the box. you still have to count allowances for devices and grounds, but if your box says "10 X #12" then it saves you the more complex math - you know you can have three 12-2 cables and a receptacle in the box. if it says "8X12" then you can't.
Another great video as usual! Michigan is currently using the 2017 NEC (adopted Jan. of 2019) I have always wondered why multiple grounds only counted as one volume allowance, but I go by the codebook. I try to use boxes with larger volumes, instead of the minimum required.
Amazing vid. In fact u should make a vid on how you would wire this entire box with everything u mention with pig tails and wago lever nuts. Now that covers a common scenario.
Great job Sparky !! Thank you for the fun walk through. I missed that new 1/4 allowance for over 4 grounds. Honestly, never heard anyone claim that the internal clamps should be counted but I see the logic. Of course, if the manufacturer listed the capacity one would think it accounted for the clamps.
Another niggling little detail. Thanks, NEC! I'd love to know what provoked this change. Now delete the approval for backstabbing. And an honest Thank you! Sparky, for working through a non-trivial example so clearly.
Hi Bill from Sparky Channel Absolutely fantastic video today Probably my favorite one yet Really enjoyed watching the math as you added up everything and what counted and how. Learning a lot from you and appreciate all your effort I’m really wondering about those built in tabs now and if they should be included or not; on a mission to find the tru answer now. Thanks for sharing your knowledge
Hi Jeff! In my internet search about 50% thought the integral clamps should be counted as box fill and 50% said no. I think it's best to count them to be safe but if you find something different please let me know. Have a great day!
Hey thank you so much for such an informative video! You made it really easy to explain!, as the code kind of makes it confusing to understand what it’s referring to at times.
Something I just learned from the Excellent Laborer was that single gang boxes have knockouts, where the double-gang boxes have the internal clamps. So, with single-gang the knockouts don't take up any internal volume but the double-gang with internal clamps take up a single volume allowance.
This could get you in trouble. IE if you only have 2 14g you would count one whereas code requires you to count that as 2. 1 up to 4 14g grounds is 2 then 1/4 for each thereafter.
Fine. It may pass inspection, but is it worth it? How about the time spent figuring this out, and carefully packing all those wires, connectors, and devices into one four square box, with a mud ring, when the sensible option (if available) is a second box location (with one device each) giving you more room & able to do the work quicker? I don't like filling a box to the max... too frustrating.
So basically each ground is 1/4 allowance. Why do they try to get fancy and tell you the first four count as 1 allowance. 1 divided by four is .25. 1/4 in decimal is .25. NEC are masters at trying to complicate the simple things in life. Maybe I’m missing something here. I dunno.
"So basically each ground is 1/4 allowance." Not quite. That is true only when the number of grounds is 4 or more. For a box with only 1 ground, the allowance due to grounds is 1. If the box has 2 grounds, the allowance due to grounds is still 1. Same for boxes with 3 or 4 grounds, 1 allowance regardless. The 1/4 math only kicks in when the ground count is over 4. But yes, a convoluted mess of a "system".
Comment......And folks wonder why the world is all screwed up..........This is a perfect example of making things more complicated than need be. Nothing against you sparky.
I've been an electrician for 40 plus years & experienced every code update and they still can't come up with a way to simplify this. How about the manufacturer provides a document stating max # of wires with what-ever devices your using. Nobody calculates this in the field. Good electricians plan their residential box layout with box fill in mind so they can install devices easily.
So the box volume calculation on a box made and sold with integral cable clamps does not subtract volume available based on the presence of those clamps?
Actually that is debatable because the NEC is not clear on that issue. Because of that us electrical contractors have to treat integral clamps like internal clamps just to be safe. So I do count them as one volume.
I don’t think half the people wiring homes in Texas follow any of these rules. They follow rules at the panel, I don’t think the inspector cares about the rest.
I’ve never enforced the clamps in plastic boxes only for metal boxes. Never looked at them as “clamps”. I don’t know if any inspectors are interpreting it in this way.
@4:32: Deletion or just an edit? Very unclear what was deleted or why the highlighting was disconnected. Not a very helpful section. Overall, the NEC seems written for people who write the NEC (or for the benefit of folks who publish actual English translations). It's often unapproachable, unhelpful, or unclear.
@@stephenholland6328: There's no excuse for bad technical writing when it could and should be clear for as wide an audience as possible, including electricians, handymen, maintenance workers, homeowners, etc.
I think it's a challenge to word any rule that can hold up to misinterpretation but the Code does sometimes seem to get mired down in traditional wording that attempts to match previous code explanations.
@@SparkyChannel actually you can. If the device is rated for 20 amps, being on a 15 am circuit won’t overload the device. It’ll trip at 15 amps Max. However you cannot do the opposite. You cannot use a 15 amp rated gfi on a 20 amp circuit. If you Maximize your circuit let’s say 19 amps, the breaker will not trip however your device may burn out because it’s only rated for 15 amps
You can always overbuild beyond your ocpd's(breaker) you just dont want to put a 15amp gfci on a 20amp breaker. In the same instance, you can always use 12awg wire on a 15amp breaker just not 14awg wire on a 20amp breaker.
Its probably a silly idea and weird question and I'm not even sure it works, but would a metal metal ring on the plastic box violate any code? I only ask because I prefer metal as you can tap new threads when a drywaller or etc lose the 6-32s and replace it with a drywall screw or I've even come across just wood screws with torx heads. I generally don't like the plastic boxes though yes they are cheaper, quicker installation, and can reduce your bid for a job making it more lucrative to secure a job, I prefer metal boxes for the reason that its easy to tap new threads and they are more solid. I've come across just going in to do a simple device replacement, swap, or even fixture and the plastic box crumbles and the threads break and strip and then have to be replaced which adds time and inconvenience and extra cost to those jobs. It would be weird having a metal mud ring on that box which I have to say I've never used or saw before this video, just the single gangs and triple gang boxes that have their individual placement of devices with their assigned screw placements.
Hi Rob! I would normally say no on the metal mud ring on the plastic box because it normally can't be bonded. However, if you were to use a devise(s) with a self grounding clip and the devise was properly grounded I think that would bond the metal mud ring so in that case I feel that it would be OK. Good luck finding an inspector to OK it though. LOL!
@@hyagosilveira987 So the ground clip will firmly, properly and completely bond to the more or less curved area of a plaster ring? I’m going to have to try this…
@@MichaelDHockenberry to answer your question, you’d use a ground clip on the plaster ring to bond it. Placement of the ground clip is your choice. I find it easier to attach it on the curve of the plaster ring where there’s no screw taking it’s spot
Grounds are conductors too. But they are not "active conductors", that's the reason they don't count in. Active conductors are only lines and neutrals. A PEN, a combined ground and neutral (in the US called MGN) is also not active, even if it carries operating current it is also a ground and carries fault currents. That would also not count in, if it would be permitted in final circuits, which it is not in the US.
@@keithweilacher4890 In the US are three colours permitted for the indentification of the ground wire: Bare copper, solid green insulation or green/yellow striped insulation. The last one is international. In Europe only green/yellow striped insulation is permitted to identify the ground wire.
However, if the receptacle is being installed in parallel, and isn’t the final device in the run, then it will require a jumper for the grounded conductor, which would bring the box full up to 38.81, meaning the box would end up a code violation. Edit: Jumpers that do not enter the box do not count, disregard.
You're making this too complex while it is quite simple: 1) A Carlon 34cu box is labeled as able to take 17x 14g wires, which are themselves 2cu. 17 x 14 is 34, meaning Carlon themselves did not count their built-in connectors. 2) No manufacturer would force an end user into accepting 4, 6, or even 8 non-removable "internal clamps", and 3) it's obvious Carlon would not include in it's cu capacity non-existent box. Metal boxes have a cu and their internal clamps are within that cu, i.e., metal box exists behind the internal clamp.
@@justinsaunders785 I believe that the rational is that conductors which do not enter or leave the box cannot affect the total power running through the box, which is what would cause heating.
@@50srefugee no argument there but if we are minding box fill due to heat that tells me (along with logic) that the more volume consumed by matter be it devices conductors etc the less available air for heat dissipation. Pig tails and jumpers would be adding to that total mass and taking away from free air for heat dissipation. The whole premise of box fill rules seem hypocritical to me.
@@SparkyChannel it’s not difficult but it does seem unnecessary. Why is there box fill rules anyways? I always assumed it was for heat dissipation. So why would they change the rule for ground allowance then? If anything the extra copper would be a heat sink no?
@@RaggedsEdge Yes, it is for heat dissipation. And yes, the copper of the ground wires would work as a heat sink until the moment they are needed as conductors in order to save the day.
@@SparkyChannel forgive me. I tend to enjoy a good discussion/ debate. I mean no disrespect by it and just like to make sure the code is being updated for the right reasons. I would argue that since the grounds would be no warmer than the current carrying conductors before an event, and that whatever event happened that would cause the grounding wires to see current, that it’s going to be a lot of current over a split second. Would that 20c warmer starting point (arbitrary number) really make a difference to an uninsulated wire? Maybe I’m just assuming that those wires are going to only see current in an event like a lightning strike or complete failure of the neutral wire and or circuit interrupting device. At the end of the day, no matter, it’s in the books. Thanks for helping explain it.
I'm a master electrician, and i can tell you that this box fill is all bullcrap to give the sense of a controlled trade regulation. It's all blatant logic, you put too many wires in your box, well you can't fit your dimmers or whatever is voluminous afterward. Simple as that. So if you are not able to visualize this in your mind, then maybe you need a code to dictate it to you. ( And i don't talk to you directly Sparky :) )
Yes, most homeowners are not able to visualize this in their minds, that's why they need the code to be able to verify what the tradie does. Simple as that.
Plastic sucks- good luck packing all that 12 gauge in there without a hammer. The NEC is a nice book of minimum standards, hey they gotta draw the line somewhere…doesn’t guarantee a quality installation though. Lol I like good old article 110-12. It should have a FPN that says. Don’t be a hammer…If you end up with a splice point for some reason with 5 wires in it. Use a metal box and only enter it from 2 sides. WWNTD? (What Would Nikola Tesla Do)
As he was talking about the ground wire calcs I was like you and thought I would need a hammer to get that 12 gauge flattened into the back of that box
Hey Sparky, Am I the only one who thinks this box FAILS meeting the requirements?? The box size is 32 cu inches and with the 5 conductors, mud ring, 5 grounds and two receptacles you have a total cu inches of 38.1 38.1 is more than 32 so it is a FAIL... right??
No, the mud ring adds 6.1 cu in to the total box area. It's close but she passes. I wouldn't stuff it that full but that's just personal preference but sometimes you gotta do what the drawings say to do if you aren't permitted free reign over design changes regarding the electrical drawings.
I’m a first year and in our commercial work they jamb pack most boxes with so many wires it’s very hard to fit them all with the devices or tightly fit blank covers without devices. Then I actually fill a box properly and it seems so empty. Sometimes packing conduit probably 90% which is more of a hindrance costing more in labor than we would save by upsizing. They just tell me it’s what the drawings call for and what our office designed so that’s what we do.
Ok this formula for calculating box fill is just incredibly stupid. The result of the calculation is basically a random number and has no correlation to actual fill. This is the dumbest thing I have seen in NEC.
@@StraitClownin909 I mean, I understand that there had to be some kind of formula, and it has to be simple enough for trade craft to calculate in the field without a lot of effort or fancy computer program. But still, this particular formula I can't fathom what the author's were thinking. Why base it on the largest conductor? That's gonna hurt if you have one big conductor in a box with lots of little ones. Box clamps count whether they take up any space or not. Some grounds are worth a whole and others are worth a quarter. Main power panel can't possibly pass this test, as it has like 40-80 conductors coming in typically, but 3 of them are 1/0 or bigger.
Enjoy your tutorials, how you calmly explain a subject and back it by the code book .
Thanks! Yes, "back it up by the book" would be a good motto.
Scotty Kilmer’ brother is an electrician?
LOL!
That's scary
😂 that’s exactly what I thought!
I was wondering if I wasn’t the only one who thought these 2 sounded way too identical 😭😭😭 and you can tell they both love what they do! Admirable!!
@@nelsonrubiano7102 me too!!! 😂
Fantastic video. Idk why yokes and clamps tripped me up but they did. Great job explaining them
Thank you for making a straight forward easy to under stand well made video.
Thanks Tim, my pleasure!
You should get to subtract for using Wago 221, and have to add if using a GFCI.
Makes sense to me.
for people interested in a cheat mode, many manufacturers will also mold a chart of allowable box fill with #14, #12, and #10 conductors inside the box. you still have to count allowances for devices and grounds, but if your box says "10 X #12" then it saves you the more complex math - you know you can have three 12-2 cables and a receptacle in the box. if it says "8X12" then you can't.
Excellent point, thanks!
Another great video as usual! Michigan is currently using the 2017 NEC (adopted Jan. of 2019) I have always wondered why multiple grounds only counted as one volume allowance, but I go by the codebook. I try to use boxes with larger volumes, instead of the minimum required.
Amazing vid. In fact u should make a vid on how you would wire this entire box with everything u mention with pig tails and wago lever nuts. Now that covers a common scenario.
Hmmm. let me thing about that one. Thanks Dave!
Great job Sparky !! Thank you for the fun walk through. I missed that new 1/4 allowance for over 4 grounds. Honestly, never heard anyone claim that the internal clamps should be counted but I see the logic. Of course, if the manufacturer listed the capacity one would think it accounted for the clamps.
Another niggling little detail. Thanks, NEC! I'd love to know what provoked this change. Now delete the approval for backstabbing. And an honest Thank you! Sparky, for working through a non-trivial example so clearly.
😜saved by the mud ring sir.
Thanks for the video.
Yes, saved by the med ring! Good one!
I think they just come up with this sizing to keep their jobs !
Made it so easy for me to understand🙏🏽🙏🏽🙏🏽
nice! how ever I expect a cram jam on some jobs due to poor wire placement inside the box....
I hope not. Thanks Joe!
Very informative post, this electrcian learned something.
Glad it was helpful!
Hi Bill from Sparky Channel
Absolutely fantastic video today
Probably my favorite one yet
Really enjoyed watching the math as you added up everything and what counted and how.
Learning a lot from you and appreciate all your effort
I’m really wondering about those built in tabs now and if they should be included or not; on a mission to find the tru answer now.
Thanks for sharing your knowledge
Hi Jeff! In my internet search about 50% thought the integral clamps should be counted as box fill and 50% said no. I think it's best to count them to be safe but if you find something different please let me know. Have a great day!
Hey thank you so much for such an informative video! You made it really easy to explain!, as the code kind of makes it confusing to understand what it’s referring to at times.
Glad it was helpful!
Something I just learned from the Excellent Laborer was that single gang boxes have knockouts, where the double-gang boxes have the internal clamps. So, with single-gang the knockouts don't take up any internal volume but the double-gang with internal clamps take up a single volume allowance.
I find its easier to remember if you just count each ground as 1/4
This could get you in trouble. IE if you only have 2 14g you would count one whereas code requires you to count that as 2. 1 up to 4 14g grounds is 2 then 1/4 for each thereafter.
Fine. It may pass inspection, but is it worth it?
How about the time spent figuring this out, and carefully packing all those wires, connectors, and devices into one four square box, with a mud ring, when the sensible option (if available) is a second box location (with one device each) giving you more room & able to do the work quicker?
I don't like filling a box to the max... too frustrating.
Hi Samuel! It was just an example to demonstrate NEC box fill rules but I do understand your sentiments.
Thanks 🙏
Thanks Peter!
What about a wire nut on the grounds? That takes up space too.
The wire nut don't count as box fill?
Yes, that's right. I know, it does sound odd.
Thanks Sparky!
This guy is my gateway to my ticket 👌🙂🙂
Do wire nuts and other forms of connectors have a fill value?
So basically each ground is 1/4 allowance. Why do they try to get fancy and tell you the first four count as 1 allowance. 1 divided by four is .25. 1/4 in decimal is .25. NEC are masters at trying to complicate the simple things in life. Maybe I’m missing something here. I dunno.
Haha, good point. I didn't think of that but it is obvious that the code could have easily just called for a 1/4 allowance per ground as you said.
wow thats so true, they must know to make it difficult for the average person reading the book
"So basically each ground is 1/4 allowance." Not quite. That is true only when the number of grounds is 4 or more. For a box with only 1 ground, the allowance due to grounds is 1. If the box has 2 grounds, the allowance due to grounds is still 1. Same for boxes with 3 or 4 grounds, 1 allowance regardless. The 1/4 math only kicks in when the ground count is over 4.
But yes, a convoluted mess of a "system".
Because the first four (no matter how many there are of that first four) count as one. So 3 = 1 not 0.75...
What about wago/ wire nuts and pig tails?
I have one question for your box. If you put 2 pigtails off the ground wire to each device do you need to add 2 more of the 1/4 allowance on box full?
Look at 4:31 and notice it only talked about ground wires entering the box. Since pigtails don't enter the box, they are not counted in box fill.
Comment......And folks wonder why the world is all screwed up..........This is a perfect example of making things more complicated than need be. Nothing against you sparky.
love your videos great job 👏 👍 👌 🙌
Thanks so much!
I've been an electrician for 40 plus years & experienced every code update and they still can't come up with a way to simplify this. How about the manufacturer provides a document stating max # of wires with what-ever devices your using. Nobody calculates this in the field. Good electricians plan their residential box layout with box fill in mind so they can install devices easily.
I did like your video Sparkey, real eye opener to how complicated it can be for a electricians to comply to the letter of the NEC.
Love to use deep boxes....
Gods work🙏🏼🙏🏼
So lets say there are only 3 ground wires would it count as 1?
Yes.
Thank you! it helps me so much!
So the box volume calculation on a box made and sold with integral cable clamps does not subtract volume available based on the presence of those clamps?
Actually that is debatable because the NEC is not clear on that issue. Because of that us electrical contractors have to treat integral clamps like internal clamps just to be safe. So I do count them as one volume.
Yeah I always figured the box manufacturer would have accounted for that volume in the stated CI. Guess we could contact Carlon.
@@RaggedsEdge Good idea.
Thanks for the education
My pleasure, thanks!
Why did you count internal clamps in a nonmetal box?
Exactly. The integral non-removable "clamps" must already be subtracted from the manufacturer's stated volume.
Perfect explanation thank you
Thank you for posting this.
You're welcome!
Your videos are great.
Thank you again, sir.
No problem, thanks Tommy!
I don’t think half the people wiring homes in Texas follow any of these rules. They follow rules at the panel, I don’t think the inspector cares about the rest.
Well needed video.
Thanks!
I’ve never enforced the clamps in plastic boxes only for metal boxes. Never looked at them as “clamps”. I don’t know if any inspectors are interpreting it in this way.
They are integral clamps but I'm sure that some inspectors don't think of them as clamps.
@@SparkyChannel ya I don’t enforce it. I look at it no different then a grey carlon boxes that have a smaller, kinda pinch type clamp. Thanks.
@@SparkyChannel Wouldn't the volume printed on the box already be reduced by the volume of the clamps and therefore not need to include them?
That was a good one bill. Good example.
Thanks so much!
@4:32: Deletion or just an edit? Very unclear what was deleted or why the highlighting was disconnected. Not a very helpful section.
Overall, the NEC seems written for people who write the NEC (or for the benefit of folks who publish actual English translations). It's often unapproachable, unhelpful, or unclear.
The NEC is written so it can be enforced by inspectors.
@@stephenholland6328: There's no excuse for bad technical writing when it could and should be clear for as wide an audience as possible, including electricians, handymen, maintenance workers, homeowners, etc.
I think it's a challenge to word any rule that can hold up to misinterpretation but the Code does sometimes seem to get mired down in traditional wording that attempts to match previous code explanations.
Greetings, your videos are very good and explanatory, thanks for posting them. I have a question, can I put a 20amp GFCI on a 15amp circuit?
Thanks! No.
@@SparkyChannel actually you can. If the device is rated for 20 amps, being on a 15 am circuit won’t overload the device. It’ll trip at 15 amps Max. However you cannot do the opposite. You cannot use a 15 amp rated gfi on a 20 amp circuit. If you Maximize your circuit let’s say 19 amps, the breaker will not trip however your device may burn out because it’s only rated for 15 amps
However you can use multiple 15 amp gfi’s on a 20 amp circuit. This only applies to one GFCI on a circuit.
You can always overbuild beyond your ocpd's(breaker) you just dont want to put a 15amp gfci on a 20amp breaker.
In the same instance, you can always use 12awg wire on a 15amp breaker just not 14awg wire on a 20amp breaker.
@@hyagosilveira987 check out the video Bill did on the subject. I think you will be surprised.
Do you have to include any wire nuts in that calculation too?
Wire nuts are not counted in box fill calc
Yes, wire nuts are counted from what I read.
@@Monuments_to_Good_Intentions Wire nuts do not count in box fill calcs.
@@Monuments_to_Good_Intentions they're not
6:10 internal clamp?
Yes, one volume fill for internal clamps.
Nice . Thanks
Thanks Lance!
Excellent explanation on this topic. Yes, It's great that you site the code references as you explain so anyone can look it up. Thank you sir
Glad it was helpful!
Great video
Thanks Azael!
good video thank you
No problem, thanks!
Its probably a silly idea and weird question and I'm not even sure it works, but would a metal metal ring on the plastic box violate any code? I only ask because I prefer metal as you can tap new threads when a drywaller or etc lose the 6-32s and replace it with a drywall screw or I've even come across just wood screws with torx heads. I generally don't like the plastic boxes though yes they are cheaper, quicker installation, and can reduce your bid for a job making it more lucrative to secure a job, I prefer metal boxes for the reason that its easy to tap new threads and they are more solid. I've come across just going in to do a simple device replacement, swap, or even fixture and the plastic box crumbles and the threads break and strip and then have to be replaced which adds time and inconvenience and extra cost to those jobs. It would be weird having a metal mud ring on that box which I have to say I've never used or saw before this video, just the single gangs and triple gang boxes that have their individual placement of devices with their assigned screw placements.
Hi Rob! I would normally say no on the metal mud ring on the plastic box because it normally can't be bonded. However, if you were to use a devise(s) with a self grounding clip and the devise was properly grounded I think that would bond the metal mud ring so in that case I feel that it would be OK. Good luck finding an inspector to OK it though. LOL!
@@SparkyChannel yeah that was my only thought haha that it would be an issue of bonding and would be flagged by an inspector
@@robfahey1349 you can bond the metal P-ring with a ground clip. Do it all the time
@@hyagosilveira987 So the ground clip will firmly, properly and completely bond to the more or less curved area of a plaster ring? I’m going to have to try this…
@@MichaelDHockenberry to answer your question, you’d use a ground clip on the plaster ring to bond it. Placement of the ground clip is your choice. I find it easier to attach it on the curve of the plaster ring where there’s no screw taking it’s spot
Sounds like a good opportunity for someone to write an app.
Yep!
Grounds are conductors too. But they are not "active conductors", that's the reason they don't count in. Active conductors are only lines and neutrals. A PEN, a combined ground and neutral (in the US called MGN) is also not active, even if it carries operating current it is also a ground and carries fault currents. That would also not count in, if it would be permitted in final circuits, which it is not in the US.
Thanks Marcel!
And here I always thought ground wires weren't counted against the allowed volume was that they were unibsulated.
@@keithweilacher4890 In the US are three colours permitted for the indentification of the ground wire: Bare copper, solid green insulation or green/yellow striped insulation. The last one is international. In Europe only green/yellow striped insulation is permitted to identify the ground wire.
Why did he add the cubic in for the mud ring ??
The square inches of the mud ring counts as well.
However, if the receptacle is being installed in parallel, and isn’t the final device in the run, then it will require a jumper for the grounded conductor, which would bring the box full up to 38.81, meaning the box would end up a code violation.
Edit: Jumpers that do not enter the box do not count, disregard.
Are you referring to pigtails in the box? I’m not sure they count, as the do not enter the box from out side.
@@donmclean1220 Rats. You’re right. That also means I’ve torn apart a few boxes that I didn’t have to. At least I know now.
it might pass but if you're using wire nuts it'll be fun getting it all stuffed in there!!!!
mmm... add some smart switches or GCFIs!! that type of box clamp takes so much space away :-/
it'll be a pain no matter what splice you use.
Thanks!
Nah it’s not gonna that bad if your organized about it and using the proper minimum length of conductors.
@@RaggedsEdge no, those boxes are a pain. The only people who think otherwise haven't used good boxes.
👍
safe
Thanks!
You're making this too complex while it is quite simple: 1) A Carlon 34cu box is labeled as able to take 17x 14g wires, which are themselves 2cu. 17 x 14 is 34, meaning Carlon themselves did not count their built-in connectors. 2) No manufacturer would force an end user into accepting 4, 6, or even 8 non-removable "internal clamps", and 3) it's obvious Carlon would not include in it's cu capacity non-existent box. Metal boxes have a cu and their internal clamps are within that cu, i.e., metal box exists behind the internal clamp.
Forgot to add 2 quarters for the device ground jumpers
only ground that enter/leave the box are counted, a jumper never leaves the box. I'm not telling you that it makes sense either, thats just how it is.
@@justinsaunders785 I believe that the rational is that conductors which do not enter or leave the box cannot affect the total power running through the box, which is what would cause heating.
@@50srefugee no argument there but if we are minding box fill due to heat that tells me (along with logic) that the more volume consumed by matter be it devices conductors etc the less available air for heat dissipation. Pig tails and jumpers would be adding to that total mass and taking away from free air for heat dissipation. The whole premise of box fill rules seem hypocritical to me.
how painful for the sparkies to dealwith this stuff
LOL! It's really not that hard. It's like when someone explains football rules to someone who has never seen a game. After a while it all makes sense.
@@SparkyChannel it’s not difficult but it does seem unnecessary. Why is there box fill rules anyways? I always assumed it was for heat dissipation. So why would they change the rule for ground allowance then? If anything the extra copper would be a heat sink no?
@@RaggedsEdge Yes, it is for heat dissipation. And yes, the copper of the ground wires would work as a heat sink until the moment they are needed as conductors in order to save the day.
@@SparkyChannel forgive me. I tend to enjoy a good discussion/ debate. I mean no disrespect by it and just like to make sure the code is being updated for the right reasons.
I would argue that since the grounds would be no warmer than the current carrying conductors before an event, and that whatever event happened that would cause the grounding wires to see current, that it’s going to be a lot of current over a split second. Would that 20c warmer starting point (arbitrary number) really make a difference to an uninsulated wire? Maybe I’m just assuming that those wires are going to only see current in an event like a lightning strike or complete failure of the neutral wire and or circuit interrupting device.
At the end of the day, no matter, it’s in the books.
Thanks for helping explain it.
@@RaggedsEdge I understand. Thanks!
I'm a master electrician, and i can tell you that this box fill is all bullcrap to give the sense of a controlled trade regulation. It's all blatant logic, you put too many wires in your box, well you can't fit your dimmers or whatever is voluminous afterward. Simple as that. So if you are not able to visualize this in your mind, then maybe you need a code to dictate it to you. ( And i don't talk to you directly Sparky :) )
Thanks Patrick!
Yes, most homeowners are not able to visualize this in their minds, that's why they need the code to be able to verify what the tradie does. Simple as that.
Ok
Thanks!
Plastic sucks- good luck packing all that 12 gauge in there without a hammer.
The NEC is a nice book of minimum standards, hey they gotta draw the line somewhere…doesn’t guarantee a quality installation though. Lol
I like good old article 110-12. It should have a FPN that says. Don’t be a hammer…If you end up with a splice point for some reason with 5 wires in it. Use a metal box and only enter it from 2 sides.
WWNTD? (What Would Nikola Tesla Do)
As he was talking about the ground wire calcs I was like you and thought I would need a hammer to get that 12 gauge flattened into the back of that box
Hey Sparky, Am I the only one who thinks this box FAILS meeting the requirements?? The box size is 32 cu inches and with the 5 conductors, mud ring, 5 grounds and two receptacles you have a total cu inches of 38.1 38.1 is more than 32 so it is a FAIL... right??
No, the mud ring adds 6.1 cu in to the total box area. It's close but she passes. I wouldn't stuff it that full but that's just personal preference but sometimes you gotta do what the drawings say to do if you aren't permitted free reign over design changes regarding the electrical drawings.
I’m a first year and in our commercial work they jamb pack most boxes with so many wires it’s very hard to fit them all with the devices or tightly fit blank covers without devices. Then I actually fill a box properly and it seems so empty. Sometimes packing conduit probably 90% which is more of a hindrance costing more in labor than we would save by upsizing. They just tell me it’s what the drawings call for and what our office designed so that’s what we do.
Ok this formula for calculating box fill is just incredibly stupid. The result of the calculation is basically a random number and has no correlation to actual fill. This is the dumbest thing I have seen in NEC.
OK, thanks.
Every single apprentice across the country is taught this crap, literally being tested on this exact stuff tomorrow.
@@StraitClownin909 I mean, I understand that there had to be some kind of formula, and it has to be simple enough for trade craft to calculate in the field without a lot of effort or fancy computer program. But still, this particular formula I can't fathom what the author's were thinking. Why base it on the largest conductor? That's gonna hurt if you have one big conductor in a box with lots of little ones. Box clamps count whether they take up any space or not. Some grounds are worth a whole and others are worth a quarter. Main power panel can't possibly pass this test, as it has like 40-80 conductors coming in typically, but 3 of them are 1/0 or bigger.
Shits getting stupid, not your video. Code reductions are really moving beyond safety to revenue generation for manufacturers...
You are 100% correct. Was thinking the exact same thing
Do
Really doesn't matter anymore you need to make your video in Spanish nobody get certified anymore everybody and their mama does electrical work